Apparatus for gaging workpieces



Jan. 29, 1963 J. w. LOVELY 3,075,293

APPARATUS FOR GAGING WORKPIECES Filed Feb. 24, 1960 3 Sheets-Sheet 1 IN VEN TOR. J/r /44/6 regg.

3 Sheets-Sheet 2 J. W. LOVELY APPARATUS FOR GAGING WORKPIECES Jan. 29, 1963 Filed Feb. 24, 1960 Aux Jan. 29, 1963 J. w; LOVELY 3,075,293

APPARATUS FoR GAGING woRKPIEcEs Filed Feb. 24, 1960 s sheets-sheet 5- INVENTOR. Jah? 144x@ V623.

United States Patent O "ice Filed Feb. 24, 1960, Ser. No.` 10,739 20 Claims.' (Cl. 33-"178) invention relates toA grinding machines, and more particularly to apparatus for gaging the sizes of workpiece bores by a sizing gage member during the grinding operation.

v 'It is an object of the present invention to provide a novel and improved arrangement for supporting a member such as a reciprocating gage plug used during a grindingoperation, which is especiallyuseful in miniature bore grindingoperations and which insures a sensitive arid accurate movement of the sizing plug.

It is anotherobject to provide an improved gaging apparatusof this type, in which the mass and friction of the reciprocating gage components are greatly reduced, thus facilitating thereciprocation of the gage plug and the rna1i iter'iance of a constant force urging the plug to its 'gagin'g position.

I-t is also an object to' provide an improved plug sizing apparatus of this character which includes novel means for permitting free oating of the gage plug to compensate f or variations in misalignment of a workpiece.

it is another object to provide an improved plug sizing unit of the above nature which enables the sizing plug to be automatically reciprocated toward and away from the workpiece in coordination with the reciprocating grinding wheel movement, thus enabling repeated gaging to take place' during' the grinding operation. Y

It is a further object to provide an improved sizing unit having the above characteristics, which permits the easy replacement of sizing plugs with those of other sizes in a quickly' interchangeable manner.

It also an object to provide an improved gaging apparatus of the above character which is of relatively uncomplicated constructior'i, is easy to install and maintain and is'du'rable in use.

Other' objects, features, and advantages of the present invention will become apparent from the subsequent de- 'scription, taken in' conjunction with the accompanying drawings,-

In the drawings:

FIGURE l is a plan view, partly in cross section and with parts broken away, taken along the line 1-1 of FIGURE 2 and's'liowi'iig the plug sizing cartridge and plug cooperating withV the workpiece;

FIGURE 2 is a side elevational view lwithfp'arts crosssec'tion'ed showing the plug shifting cylinder as Well as the follower rod;

FI' URE A3 i's an end elevationalfview taken in the directi'on ofthe arrow 3 of FIGURE 2' and showing the relative locations of the shifting cylinder, the follower rod aridithe plug sizin'gcartridge'; and

FIGURE 4 is. an enla'ri'g'edv fragmentary cross-sectional view similar to a portion of FIGURE 1' and showing the plug -sizing cartridge and its component parts.

InA general'- terr'n's, the invention comprises a xture mountableV on ag'rinding machine, `for example a centerless grinder for finishing the internal surfaces of parts s'uch asV` miniature beariiigfr'aces. The device includes a follower' engageable with the wheelhead and movable in a direction parallel to the reciprocating grinding wheel movement, that is, parallel' tothe work axis. The follower is secured to` a plug' sizing cartridge, this cartridge carrying asizing gage plug insertable' into thev workpiece when the, internal surface thereof has been' enlarged to the proper' dir'iien'sion or diameter. A shifting'rnotor is pro- Patented Jan. 29, 1963 vided in the form of a piston and cylinder for shifting the follower and cartridge toward and away from their operative positions.

The cartridge,A which is Asupported in a replaceable manner by a stationary guide, is so constructed as to require that a minimum of mass and friction be overcome when moving the 'plug` This is accomplishedby supporting an elongated plug holder at one end of the cartridge by a bearing which permits rocking movement of the holder, and supporting theintermediated portion ofthe holder by an air cushion orbearing, so that the plug held at the outer end ofthe holder may shift to compensate for misalignment of the workpiece. In operation, the follower and cartridge will move away from the workpiece as thev grindingwheel approaches and enters the workpiece, and will move toward the workpiece each time the grinding wheel is withdrawn; this being accomplished by a spring which urges the follower Vrod against the wheelhead. Another spring is so mounted within the cartridge as tourge the plug holder and plug against the workpiece, so that the gaging plug may enter the workpiece when the inner diameter of the workpiece has been suici-ently enlarged, a minimum of force being required in view of the low mass and friction which must be overcome.

, Referring more particularly to the drawings, the device is generally indicated at 11 (FIGURE 2,) and comprises a base l2 which may be secured to a grinding ,machine indicated in dot-dash lines at 13. For illustrative pur'- .pose,s, the grinding machine is shown Aas having a wheelheadvindicated in `dot-dashlines at 14 which carries a spindle 15 with a grinding wheel 16 adapted to enter the bore of a workpiece 17 such as a miniature bearing race;

The base 12 carries a Vr follower rod 18 which is slidably supported by vbearings 19 in a bore 2 1 having an axis parallel to the spindle axis andiri the direction of reciprocating movement of the wheelheacb RodlS carries `an outer member 22 engageable witha pad 23carriedby a bracket 24 secured to wheelheadlft. A helical compression spring 25 is4 vengageable with the opposite end o f rod 18, this spring being disposed between oneendZQ of a bracket 2'7 (FIGURE l) and a collar 2S securedto rod 1 8, and urgingthe rod into engagement with pad 23. Bracket 2'7 is secured to base 12 by bolts 2,9, as seen in FIGURE 2. The arrangement is therefore such Ithat when rod 18 is permitted tocome in contact with p ad 23 is will follow the" reciprocating motion of wheelhead I4.

A reciprocablel shifting motor generally indicated atl 3 1 is provided above; rod 18', this motor servingto shift the follower rdb'e'tween aretr'acted andan operative ,posif tion, the `operative' positionbeing shown in FIGURE Motor' 3:1` comprises a cylinder 32 secured to'base 1,2 anld a piston '33 slidably mounted in the cylinder. Piston 33 has al rod- 34v extending t'o the rightl through a bearing 3S in oi'ie end' of cylinder 32, a helical compression spring 3'6`whivc'h is stronger than spring ZS'beir'ig disposed between bearing 35 and thelpiston. A second rodjsn extends' to the left from piston 33 through a'n' end cap 38' inthe cylinder, andv a `cc'in'nectin'g plate 3 9 Hasi a one-way connection with rod 37' by' means of a,set` sc'r`ew 41 which butsy the r'o'df.` Plate39' is -of generally' L-'shaped configuration' as s e'enf iniiGURE s anais securedibeoiiar 2s by means sueii as' al we id 42', afs geen in FIGURE 1. The iojwer emi of plate 39`is securable toa plug sizing",cartridgev generally indicated at' 43", which carries the g'a'girigplug.

Cartridge 43" comprises' a' housing 44' of cylindrical shapewhich is slida'ble' in a' cartridge guide 4S fixed to base" 12, as seen in'FIGUR' 1. Guide' {limer/ besecur'ed tobase 12 by means suoli as a'clampoandabolt 6,8'. The l'eft end'of housing is provided with a'shoulder 46v s'ecurable to connecting plate 39 a bolt 45. A C- shaped leaf spring 48 is secured to shoulder 46 by bolt 47 and a bolt 49, this leaf spring being engageable with opposite edges of connecting plate 39, as seen in FIGURE 2. The rear portion of housing 44 has an internally threaded bore 51 within which is disposed an adjustable stop 52 having a knob 53 accessible from the rear of the device. This stop is engageable by the left end of a helical compression spring 54 disposed within housing 44, the right end of spring 54 engaging a collar 55 which carries the outer race of an anti-friction bearing 56. Collar 55 is of smaller diameter than the bore within which it is disposed. A sizing plug holder 57 is secured to the inner race of bearing 56 and extends to the right through a bore 58 of larger diameter than holder 57. The outer end of holder 57 is adapted to carry a sizing gage plug 59 which may enter workpiece 17 when holder 57 moves to the right. Bearing 56 is a combined radial and thrust bearing permitting limited rocking movement of holder 57 A compressed air connection 61 is provided -in base 12 as is seen in FIGURE 1 and connects with a passage 62 leading to an annular passage 63 concentric with bore 58. Annular passage 63 leads to a plurality of radial passages 64 which connect with bore 5S. An air bearing is thus provided for holder S7 which, while supporting the holder concentrically within the bore, will permit limited lateral shifting or rocking motion of the holder, this motion being centered about bearing 56. Plug S9 extends through a guide or backing plate 65 for workpiece 17, which plate is provided with a clearance aperture of suflicient size to permit this lateral shifting. A clearance aperture 66 is also provided at the forward end of housing 44 for holder 57. It will thus be observed that the holder has to overcome very little friction when moving in a direction parallel to its axis, in that the total mass of parts which are moved by spring 54 is quite low.

In order to provide a signal for retracting wheelhead 14 and plug 59 after plug 59 has entered workpiece 17, a passage 69 is provided which carries a contact wire 71 into base 12, this contact wire being in electrically conductive relation with a contact 72 located adjacent guide 45. Contact 72 is carried by a leaf spring 73 the outer end of which is engageable with bearing 56, and the contact is disposed adjacent second contact 74. The disposition of the parts is such that when bearing 56 is shifted to the right as shown in FIGURE 1, contact 72 will be separated from contact 74, thus opening a circuit which by relay means shown schematically at 80 causes retraction of wheelhead 14 and exhaustion of chamber 76.

In operation, piston 33 will normally be in its retracted position as -urged by spring 36, this position being to the left of that shown in FIGURE 2. A compressed air port 75 is provided for ychamber 76 of cylinder 32, and pressurizing of this chamber will cause piston 33 to shift to the right against the urging of spring 36. The rightward shifting -of piston rod 37 will cause plate 39 to shift to the right and with it follower rod 18. This rod will thus come into contact with pad 23 of wheelhead 14, and the maintenance of pressure in chamber 76 will cause follower rod 18 to maintain its engagement with pad 23 during the reciproca-ting movement of wheelhead 14.

The rightward movement of plate 39 in FIGURES 1 and 2 will cause cartridge 43 to move to the right until sizing plug 59 is located adjacent workpiece 17. By means of adjusting knob 53 and the other adjustable parts of the mechanism, sizing plug 59 is so located that when in its `operative position, as shown in FIGURES 1 and 4, it will attempt to enter workpiece 17 as grinding wheel 16 is withdrawn to the right, but will leave the workpiece when the grinding Wheel enters the workpiece.

During the first part of the grinding operation, the internal diameter of the workpiece 17 will normally be too small -to permit gage 59 to enter. The gage will therefore engage the adjacent side of workpiece 17 and further movement of housing 44 to the right will result in partial deection of spring 54. This spring being relatively weaker than spring 25, it willbe seen that plug 59 is urged into the workpiece bore with a relatively light force. Since the air bearing comprising bore 5S is pressurized, this bearing will support holder 57 in a frictionless manner, permitting rocking movement about anti-friction bearing 56 lto compensate for yany misalignment of the workpiece bore with respect to the axis of cartridge 43. It should be kept in mind that spring 25 will not exert a force on sizing plug 59, since the force of spring 25 is transmitted directly to pad 23 through rod 18, The sliding friction of housing 44 within guide 45 will also not affect the movement of plug 59 since spring 54 acts directly on bearing holder 55.

When the bore of workpiece 17 has been enlarged to the proper diameter, the next forward movement of plug 59 will result in its entering the bore. Holder 57 will move along with the plug as urged by spring 54 and will flex spring 73 to open contacts 72 and 74 and cause re traction of wheelhead 14. Chamber 76 will also be depressurized by opening of this switch, permitting spring 36 to retract the follower rod and cartridge 43 to their retracted positions against the urging of spring 25. Withdrawal of plug 59 from the bore of workpiece 17 will permit the workpiece to be discharged from the machine.

Should it be desired to replace the sizing plug with one of a -dilferent diameter, this may be easily done by replacing cartridge 43 with another cartridge having the same external size so that it may lit within support 45. Cartridge 43 may be removed simply by removing bolt 47 and lifting spring 48.

While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

l. In a device for gaging workpieces, a gaging member, resilient means urging said member in a direction of move-v Iment toward a workpiece location, and yieldable means urging said member toward a central axial position and supporting said member for rocking movement in any direction transverse to said direction of movement.

2. In an apparatus for gaging workpieces, a gaging member, an elongated holder supporting said member and having a central longitudinal axis, iirst supporting means at one end of said holder permitting limited rocking movement, and intermediate supporting means comprising yieldable means urging said member toward a central posi-tion and supporting an intermediate portion of said holder for said limited rocking movement in any direction transverse to the axis of said holder.

3. The combination according to claim 2, further provided With resilient means urging said holder in an axial direction.

4. The combination according to claim 2, said yieldable means comprising a compressed -air bearing supporting s aid holder along an intermediate portion thereof.

5. The combination according to claim 2, said first supporting means comprising an anti-friction bearing, said intermediate supporting means comprising an air bearlng.

6. In an apparatus for lgaging workpieces, a housing, a gaging member holder extending from sa-id housing and having a central longitudinal axis, a rockable bearing support within said housing for the inner end of said holder, intermediate supporting means comprising yieldable means urging said member toward a central axial position and supporting an intermediate portion of said holder in a direction transverse to its axis, a spring within said housing urging said holder outwardly, and means for selectively adjusting the force of said spring.

7. In an apparatus for gaging workpieces, a housing, a. gaging member holder extending from said housing and having a central longitudinal axis, a rockable bearing support within said housing for the inner end of said holder, intermediate supporting means comprising yieldable means supporting an intermediate portion of said holder in a direction transverse to its axis, a spring within said housing urging said holder outwardly, means for selectively adjusting the force of said spring, a support for said housing, and means for moving said housing between retracted and operative positions on said support.

8. The combination according to claim 7, further provided with a follower member connected to said housing and adapted to engage a grinding machine wheelhead.

9. The combination according to claim 8, further provided with means for shifting said housing and follower member between a retracted position in which the follower member is separated from the grinding machine wheelhead and an operative position in which the follower member is in constant engagement with said wheelhead.

10. The combination according to claim 6, said intermediate supporting means comprising an air bearing carried by said housing.

l1. In an apparatus for gaging workpieces, a base, a reciprocable shifting motor carried by said base, a follower member connected to said motor, the motor being movable between a first position in which the follower member is retracted and a second position in which the follower member is in continuous engagement with a grinding machine wheelhead, a cartridge connected to said follower member, a sizing plug holder extending from said cartridge in the direction of movement of said follower member and having a central longitudinal axis, a rockable support at the inner end of said holder, yieldable supporting means at an intermediate portion of said holder, the outer portion of said holder being adapted to hold a sizing plug, a cartridge spring within said cartridge urging said holder in the direction of its axis, and a support on said base for said cartridge.

12. The combination according to claim 11, the connection between said follower member and cartridge comprising an elongated member, and means removably securing said cartridge to said member, whereby the cartridge may be interchanged with another cartridge.

13. The combination according to claim 1l, said shifting motor comprising a piston and cylinder, a fluid connection on one side of said piston for urging the piston towards an operative position, and a spring urging the piston toward its retracted position.

14. The combination according to claim 11, said follower member comprising a rod slidably mounted on said base, and a follower rod spring urging said rod toward its operative position, said cartridge spring being substantially weaker than said follower rod spring.

15. The combination according to claim 11, further provided with means responsive to entry of said sizing plug into a workpiece for causing retraction of said wheelhead and movement of said motor to its rst position.

16. In an apparatus for gaging workpieces, a base, a reciprocable shifting motor on said base comprising piston and cylinder members, a fluid connection for urging said motor in one direction, a motor spring urging the motor in the opposite direction, a follower rod connected to said motor and extending in parallel relation therewith, said follower rod being adapted to engage a grinding machine wheelhead when moved in said one direction by said motor, a follower rod spring urging said follower rod in said one direction, said motor spring being of greater strength than said follower rod spring, an annular cartridge support carried by lsaid base, a cartridge slidably mounted in said support and connected to said follower rod for movement therewith, a stop carried by said cartridge adjustable in a direction parallel to the direction of movement of said follower rod, a spring disposed in said cartridge and having one end supported by said stop, a cylindrical sizing plug holder of elongated shape extending from said cartridge, a rockable support comprising an anti-friction bearing within said cartridge and supporting the inner end of said holder so as to permit limited rocking movement thereof, said spring urging said rockable support in said one direction, and an air bearing radially supporting an intermediate portion of said holder so as to permit said rocking movement to take place.

17. In a device for gaging workpieces, said device comprising a gaging member mounted in one end of an elongated holder, said holder having a lengthwise axis, a support means for said holder urging said member toward a central axial position and being yieldable to permit limited radial and angular motion of said axis, a resilient means exerting an axial force on said gaging member in a direction toward a workpiece location, and a connecting means mounted at the opposite end of said holder from the gaging member receiving the axial force exerted by said resilient means receiving the axial force required to move the gaging member in a direction away from the workpiece location permitting rotation of the gaging member.

18. The combination according to claim 17, having the resilient means limiting it-s axial force to substantially that required to urge the gaging member in a direction toward the workpiece location, and a gaging member withdrawal means adapted to move said member in a direction away from said workpiece location and to permit motion of the member in a direction toward said location.

19. The combination according to claim 18, having the Isaid support means comprising a fluid bearing whereby friction force opposing motion of the gaging member toward said workpiece location is minimized.

20. The combination according to claim 19, having the said connecting means comprising an anti-friction ball bearing.

References Cited in the file of this patent UNITED STATES PATENTS 1,516,124 Schlaupitz Nov. 18, 1924 2,321,903 Fox June 15, 1943 2,787,866 Gross Apr. 9, 1957 

16. IN AN APPARATUS FOR GAGING WORKPIECES, A BASE, A RECIPROCABLE SHIFTING MOTOR ON SAID BASE COMPRISING PISTON AND CYLINDER MEMBERS, A FLUID CONNECTION FOR URGING SAID MOTOR IN ONE DIRECTION, A MOTOR SPRING URGING THE MOTOR IN THE OPPOSITE DIRECTION, A FOLLOWER ROD CONNECTED TO SAID MOTOR AND EXTENDING IN PARALLEL RELATION THEREWITH, SAID FOLLOWER ROD BEING ADAPTED TO ENGAGE A GRINDING MACHINE WHEELHEAD WHEN MOVED IN SAID ONE DIRECTION BY SAID MOTOR, A FOLLOWER ROD SPRING URGING SAID FOLLOWER ROD IN SAID ONE DIRECTION, SAID MOTOR SPRING BEING OF GREATER STRENGTH THAN SAID FOLLOWER ROD SPRING, AN ANNULAR CARTRIDGE SUPPORT CARRIED BY SAID BASE, A CARTRIDGE SLIDABLY MOUNTED IN SAID SUPPORT AND CONNECTED TO SAID FOLLOWER ROD FOR MOVEMENT THEREWITH, A STOP CARRIED BY SAID CARTRIDGE ADJUSTABLE IN A DIRECTION PARALLEL TO THE DIRECTION OF MOVEMENT OF SAID FOLLOWER ROD, A SPRING DISPOSED IN SAID CARTRIDGE AND HAVING ONE END SUPPORTED BY SAID STOP, A CYLINDRICAL SIZING PLUG HOLDER OF ELONGATED SHAPE EXTENDING FROM SAID CARTRIDGE, A ROCKABLE SUPPORT COMPRISING AN ANTI-FRICTION BEARING WITHIN SAID CARTRIDGE AND SUPPORTING THE INNER END OF SAID HOLDER SO AS TO PERMIT LIMITED ROCKING MOVEMENT THEREOF, SAID SPRING URGING SAID ROCKABLE SUPPORT IN SAID ONE DIRECTION, AND AN AIR BEARING RADIALLY SUPPORTING AN INTERMEDIATE PORTION OF SAID HOLDER SO AS TO PERMIT SAID ROCKING MOVEMENT TO TAKE PLACE. 